The packages of electronic components (hereinafter referred to as electronic component packages) such as piezoelectric resonator devices have their inner spaces hermetically enclosed in order to prevent property degradation of the electrodes of the electronic component elements mounted in the inner spaces.
An electronic component package of this kind includes two sealing members such as a base and a lid. The base and the lid define a package in the form of a rectangular parallelepiped. In the inner space of the electronic component package, an electronic component element such as a piezoelectric resonator plate is bonded to and held by the base. The bonding of the base and the lid hermetically encloses the electrodes of the electronic component element in the inner space of the electronic component package.
For example, Patent Document 1 discloses a crystal component (an electronic component of the present invention) that includes an electronic component package defined by the base and the lid. In the inner space of the electronic component package, a crystal plate is hermetically enclosed. The crystal component includes a base that has through holes passing through a base material of the base. Each through hole includes, on its inner side surface, a wiring metal made of a multiple-layer metal film such as Cr—Ni—Au. Each through hole further includes an alloy such as AuGe welded therein, thus securing air tightness of the inner space of the electronic component package.